Ecocentric

Scientists Discover a Mega-Canyon Beneath the Melting Ice Sheets of Greenland

Using radar and radio, researchers uncovered a previously unknown canyon that runs down the middle of the frozen continent of Greenland. It could play a role in the dispersion of melting water from the ice sheet.

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Image courtesy of J. Bamber, University of Bristol

A 3-D rendering of the under-ice canyon discovered in Greenland

As its name suggests, the Grand Canyon is pretty grand, running nearly 300 miles long, with a width that ranges from 4 to 18 miles and a depth of over a mile. Theodore Roosevelt, who declared the Grand Canyon a national monument in 1908, said the great gorge was a “natural wonder which is in kind absolutely unparalleled throughout the rest of the world.”

True enough. But the Grand Canyon may have some new company. Researchers from Canada and Britain announced that they discovered a massive new canyon underneath the thick ice sheet that covers most of Greenland. The still unnamed canyon, which snakes its way up through the center of Greenland and empties past the northern coastline, is some 500 miles long and up to half a mile deep, putting it on the same scale as the Grand Canyon. It may be that the previously undiscovered canyon could play a role in transporting the sub-glacial meltwater produced by Greenland’s dwindling ice sheet into the surrounding ocean, which acts to raise global sea levels.

Indeed, the original purpose of the research that uncovered the canyon—published in the journal Science yesterday—was to help answer one of the most pressing problems facing climate scientists: how will the sprawling Greenland ice sheet, which holds enough frozen water to raise sea levels by 20 ft. if it all melted, react to rising global temperatures? But the result of the research is even more amazing: in an age where we have cameras on every street corner and satellites can peer down to the square inch, who would have believed that a giant canyon still remained to be uncovered?

 Professor David Vaughn of the British Antarctic Survey noted in a statement just how remarkable the discovery was:

A discovery of this nature shows that the Earth has not yet given up all its secrets. A 750km canyon preserved under the ice for millions of years is a breathtaking find in itself, but this research is also important in furthering our understanding of Greenland’s past. This area’s ice sheet contributes to sea level rise and this work can help us put current changes in context.

The canyon isn’t visible from above, as its locked beneath the ice sheet. But the researchers were able to find it by using radar in overflights, bouncing signals off the bedrock underneath the ice. (At certain frequencies, ice is functionally transparent to radio waves.) In the warmer geologic past, when far less ice covered Greenland, the canyon would have carried a rushing river up the center of the island, just as the Colorado River flows through the Grand Canyon today.

The discovery never would have been possible without NASA‘s Operation IceBridge, the largest-ever airborne survey of Earth’s polar ice, as well as an excellently named research project. IceBridge captured an enormous amount of data about Greenland’s ice cover, which was added to additional datasets to create a comprehensive assessment. This is science in the Big Data era—researchers are able to collect vast amounts of information and then pull the unexpected out of them.

Since it’s covered with almost three miles of ice, no human being will lay eyes on the actual Greenland canyon, so radar images will have to do for now. Unless of course the ice sheet does finally melt. But if that happens, we may have more to worry about then sightseeing.

6 comments
JKBullis
JKBullis

Arctic sea ice seems to be dwindling and this is reasonably connected to the fact that ocean heat content is increasing.

Greenland is not under water and the same connection to the sea does not exist.  To say that the Greenland ice sheet is 'dwindling' is over-reaching beyond any current evidence. 

It is hard enough to get a serious discussion going about how to deal with CO2 in the atmosphere without such nonsense clogging up the discussion.

We could do significant things by establishing standing forests to replace all that cut down, though the more likely places to do this would be in the under-used areas of North America.  Water would be needed, which we have plenty of, though some sensible projects to put it in the right places are necessary.

dscho7
dscho7

Although not seen previously in this detail, basically this subglacial topography, referred previously as a basin, is not formed from erosion, but from melting at the bed of the ice that simply gravitionally reaches the lowest extreme of the basin and seeps; whose axis is determined by the ice thickness that depresses the subsurface.  So really this is not a canyon, but actually a basin. 

reidh
reidh

Never will be seen. Not even close. But you should be made to move there and watch it, Bryan you geekfag

mark120953
mark120953

What an idiotic comment from someone picking on the editing or language error rather than the implications of the Greenland canyon discovery. Lots of folks care what happens with climate change and at least Time is staying focused on how Science and Research can play a role in alleviating harm. Down here in Tampa-Clearwater,Florida,we all know something is changing even if we get the same afternoon storms and humidity we normally get and have been lucky to avoid a hurricane for years. The Florida Governor is despite low popularity trying to improve water supply for the Everglades region and sue Georgia for diverting water from the Appalachicola region. More seagrass has been planted in the Bay area to help with wave pressure increasing but nobody is naive to think our luck will continue indefinitely. Insurers still won't return to Florida and write property coverage for homeowners so we are stuck with the last resort Citizens Insurance,a state government entity which is about to raise rates at least 7 percent while encouraging some policyholders to transfer to not so reputable underwriters. Stay tuned.

jkjk
jkjk

Does anyone copy-edit for Time's Senior Editors?  

"The canyon isn’t visible from above, as IT'S (not "its") locked beneath the ice sheet."

"...
we may have more to worry about THAN (not "then") sightseeing."

Does anyone learn proper grammar and spelling these days?